The amount of a ubiquinone biosynthesis protein COQ9, mitochondrial (human) when measured in cerebrospinal fluid. The trait is level of ubiquinone biosynthesis protein COQ9, mitochondrial (human) in cerebrospinal fluid (Ontology of Biological Attributes term OBA_2056332). Also known as: cerebrospinal fluid ubiquinone biosynthesis protein COQ9, mitochondrial (human) amount.